Lathe-dog



H. SMI-TH.

LATHE DOG.

APPLICATION FILED JAN. 26. 1920.

1,367 ,284'. Patented Feb. 1, 19211. i l 2 l 5 i ",f/ 4 *W l ,34 O LII10 J' PATENT OFFICE.

HARRY SMITH, 0F SHE'FFIELD, ENGLAND.

LATER-DOG.

Speciiication of Letters Patent. i

Patenten. ren. i.. inet.

Application filed January .0.6, 192i). Serial No. 354,314.

To all Lc/01m it may concern Be it known that I, HARRY Sierra, a subjectof the King oit England, residing at Sheliield, England, have inventedcertain new and useful Improvements in Lathe- Dogs, o'l' which thefollowing is a specilicat-ion.

This invention relates to lathe dogs and the like of the kind employedto assist in transmitting power from the lathe or other machine to thework, the object of the invention. being to provide improvements in theconstruction of the dog in which parts subject to wear may be easilyremoved and re.- newed.

According to the present invention the dog is made in two main partswhich are bolted, screwed or otherwise clamped togetherv the division oithe dog being across the axis ot lthe aperture which receives the workto be rotated in the machine. A. renewable nut tor the clamping setscrew is provided and is held between the two main parts of the dog,rotation ol the nut `in relation to the dog being prevented by wholly orpartially inclosing the nut in a suitably shaped enlarged part of a holepartially made in both the two main parts oli the doe. lVhen a renewablegripping piece is used it may be provided with a web or flange to beheld or clamped between the two main parts ci? the deff. i

lh the accompanying drawings Figure 1 is a plan of a dog according tothe present invention, one oit the two main parts having been removed.

Fig. 2 is a section through the dogon the line 2-2 of Fig. 1.

Fig. 3 is a section through the dog 0n the line 3-3 of Fig. 1.

Fig. 4 is a similarview to Fig. 1 showing a modilication, the nut beingshown in section.

Like reference numerals indicate like parts throughout the drawings.

ln 'carrying out the present invention the dog is made in two main parts1 and 2 which are clamped together by set screws 16, the division of thedog being across the axis of the aperture 3 which receives the work tobe rotated in the machine, as seen clearly "in Figs. l and 2. i

The hole L1to1' the set screw 5 to clamp the work in the aperture B isnot tapped as in the ordinary construction of dog but is madesufficiently large for the set screw 5 to pass 'reelythrough it. Theholelis 'formed partially in both of the two main, parts l and 2 of thedog and at a convenient part or its length. is enlarged into a recess 6.it. re-v newable tapped nut 'l' for the clamping set screw 5 is providedand is inclosed in the hole 4 and recess 6 between the two members. 1and 2. The nut 7 is held against longi tudinal movement by means oi acollar or the like 8 formed thereon and engaging the recess 6. Rotation'oli the nut in ielatifin te the dog is prevented by :torining the collar8 with a tlat or flats 9 engaging a corre sponding hat part ol? therecess 6.

Although it is preferred thus to make the nut 7 in the form of a tappedbush having a collar 8 it will be understood that it' desired the nutmay correspond in shape to the re cess G andbe wholly inclosed therein.

A renewable gripping piece 10 may, it de sired, also be provided with adog according to this invention by recessing the t vo main parte 1 and 2oli the dog around `the were; carrying aperture 3, on that part olf theaperture opposite the clamping screw shown at 11 in Fig. 17 the dottedline 13 in-` dicating the part ol' the aperture thus Je` eessed and itsshape when. the renewable gripping piece is not provided. rlhe grippingpiece10 may be oli any desired shape. and formation5 that partcontacting with the work being suitably grooved and shaped. in any knownmanner either as an angle as shown or as an arc oi a circle orotherwise. The gripping piece is secured in its recess by forming itwith a web or flange 12 entering` a continuation oi' the recess 11 andengaged by the set screws or belts 16. Or, the web 12 may be formed witha flange or rejection engaging a corresponding recess 1n the dog.Although the web 12 is shown central and the continuation or" the recess11 partially formed in both members 1 and 2, the continuation may be inone or these members only by suitably arranging the position of the web.

In the modification illustrated in Fig. i the renewable nut 7 is made inthe form of a tapped bush having a head 14 correspond ing to the collar8 and engaging the recess G, which in this case is made where the hole djoins the aperture 3. The tapped bush may be held in place by a grubscrew 15 and rotation of the bush in the dog may be prevented either bythe grub screw 15 or by suitably shaping the head 111 and recess 6.

Where this construction is employed the dog may be made in one pieceprovided the bush is not made too long to be inserted into the hole 4through the aperture 3.

By the employment of the present invention it will be appreciated thatwhen the threads .ot the set screw 5 and its nut become worn these vparts may be easily removed and replaced by a new nut and screw, theoperation formerly necessary of boring out the tapped hole in the dogand re-tapping it being thus avoided. Similarly, the gripping piece lmay also be renewed when desired or replaced by one et different shape.

If desired the dog may be formed to inclose more than one ot theclamping screws each with its renewable nut.

The two members l and 2 of the dog will .conveniently be cast, althoughin vsome cases they maybe forged, their contacting surfaces beingsuitably machined.

W hat l claim ano desire to secure by Letters Patent is l. Thecombination of a lathe dog divided into two main parts across the axisof the work receiving aperture, means for clamping them together, a.renewable nut for the clamping set screw inciosed between the said mainDarts and means for areventine l r3 rotation of the nnt in relation tothe dog substantially as specnied.

2. The combination of a lathe dog divided into two main parts across theaxis or" the Y work receiving aperture, means for clamping themtogether, a renewable nut for the clamping set-screw inclosed betweenthe said main parts, means for preventing rotation oit the nut inrelation to the dog and a renewable gripping piece having a web heldbetween the two main parts ot' the dog substantially as specified.

3. The combination of'a lathe dog divided into two main parts across theaxis of the work receiving aperture, means Jr'or clamping them together,a renewable nut for the clampingset screw in the forni of a tapped bushinclosed in a recess partially formed in s tation of the nut in relationto each of the two main parts and provided with a collar engaging anenlargement oi" the said recess and means Ylor preventing iothe dogsubstantially as specified.

el. The combination or a lathe dog divided into two inain parts acrossthe axis of the work receiving aperture, means for clamping themtogether, a renewable nut for the clamping` set s: rew in the form ol' atapped bush iiiclosed in a recess partially formed in each of the twomain parts and provided with a collar having a` liat tace engaging anenlargement or the said recess substantially as speciiied.

5. The combination ot a lathe dog divided into two main parts across theaxis or the work receiving aperture, means ior clamping them together, arenewable nut for the clamping set screw in the iform of a tapped bushinclosed in a recess partially formed in each of the two main parts andprovided with acollar having a ilat face engaging an enlargement of thesaid recess and a renewable gripping piece having a web held between thetwo main parts of the dbg substantially as spefiiied.

6. The combination of a lathe dog divided into two inain parts acrossthe axis of the work r ceiving aperture` bolts .securing the two inainparts of the dog together, a renewable nut for the clamping set screw inthe form oi a tapped bush inclosed in a recess partially formed in eachot the two main parts and provided with a collar having a flat faceengaging an enlargement ot the said recess and a renewable grippingpiece having a web held between the two main parts orn the dog andengaged by the securing bolts substantially as specified.

In testimony whereof I have, signed my name to this specification in thepresence of' two subscribing` witnesses.

HARRY SMITH.

llfitnesses r PRICE K. EVANS, ARTHUR H. GREENWOOD.

